As grassroots NGOs get their lobbying smarts in gear for the June 20 G20 Summit, set to unfold just minutes from where I sit writing this, a hefty number from around the world will be focusing on the so-called Robin Hood tax that made its way into the headlines earlier this week.

I’m talking here about the idea of a worldwide financial transactions tax on stock and currency trading — a levy many politicians, economists, global activists and business minds believe is the path to social and climate justice in both the developing and developed world.

True, the concept’s hitting some bumps. It had big buzz before finance ministers, preparing for June’s G20 Summit, met in Washington last weekend.

But now that the meet is over, it looks like heads of state of Australia, Japan, Brazil and sadly, worst of all, Canada, are aiming to kill the best hope we have in these precarious times, even though we are talking a barely perceptible ding of 25 to 50 cents on every $1,000 in transactions.

The new tax wouldn’t affect ordinary investors. It’s only the huge traders in play every minute — the very risk-takers most requiring a restraining hand — who would notice it.

But by slicing the world’s big interconnected issues into separate silos, Stephen Harper’s team seems to have won this round. The global financial transaction tax (akin to what was formerly called the Tobin tax) should have been crowned this year’s “most likely to succeed” at June’s G20, but now it looks to be losing blood.

The momentum so far has been amazing. The push for the tax got a surprise resuscitation at the last G20 in Pittsburgh after lying dormant for decades because economic “realists” believed the idea of global coordination was utopian at best.

The concept picked up speed in Copenhagen in December as leaders made commitments to fund mitigation and adaptation in the developing world with a wad that would build to at least $100 billion annually by 2020.

It was obvious to everyone but Stephen Harper that new financial instruments would have to be created to fulfill the developing world’s basic requirements if there’s to be any climate change deal. This is exactly where the appropriate linkage between environmental justice/transformation and the need for financial reform becomes clear.

Good on the Europeans, who seem more equipped than Canada to grasp a whole-picture, long-term perspective. The EU passed a resolution in favour of the new tax just last week. And the IMF was expected to follow suit.

But here’s where the sneaky issue of “mandate” comes in. If you carve off the enviro side of the tax plan and see it only as a financial reform aiming to restrain speculation risk, you lose the oxygen that breathes the life into it.

Proponents of the tax, backed by a huge grassroots campaign in the non-profit world, see it as a relatively pain-free way to generate a huge stockpile of cash — estimates vary from $400 to $700 billion per year. That could go a long way to seriously addressing major world problems.

Supporters including Warren Buffett and George Soros generally see half these dollars going to healthy strides against poverty and climate change in the developing world. The rest would enter home-country coffers, where it could be put to use by deficit-strapped governments to extend social and environmental progress.

That’s just plain smart. I’m sorry, but some truths really are self-evident. Right now, the most obvious one is that governments need more resources to deal with issues like rising health care costs, let alone seeding energy-efficiency and other climate measures. Simple as ABC.

There’s no other way to tackle global poverty and unemployment, climate change and environmental degradation.

If Canada, et al., succeed in sabotaging this seismic change, they will have choked off all visions of the future. And, by the way, in business terms, that represents significant risk exposure for the Canadian economy and for the financial industry that feeds on it – over the short, medium and long term.

The IMF pulled back from supporting the tax, however. And the reason is interesting. Its report states that though “there may indeed be a case [for it], an FTT [Financial Transaction Tax] does not appear well suited to the specific purposes set out in the mandate from G20 leaders.” Yes, the mandate was to relate only to the cost of “interventions to repair the banking system.”

Somehow, world leaders failed to include the global public sector’s need in the IMF mandate, even though the IMF estimates that the crisis will largely be the cause of a 40 percentage point rise relative to GDP in developed nations’ government indebtedness by 2015. Yikes.

This is what gives Finance Minister Jim Flaherty and Harper the head of steam to frame their opposition to the initiative in their own reductionist and misleading way, saying that because Canadian banks weathered the crisis, such a tax is irrelevant to this country.

But here’s the good news. I know it doesn’t feel like much of a rainbow, but if we don’t blow it, there could still be a pot of gold waiting for us at the end of the Toronto G20. If social and political pressure from around the world can build awareness of what this amazing initiative represents, much bigger players than Harper might make some real progress.

But remaining conscious of the connection between climate, poverty and financial reform is key.

The financial sector has outgrown its britches over the last 10 years, gobbling up a huge unproductive share of the economy. In comparison to how lucrative this sector is, it’s hugely under-taxed. We don’t buy a bag of chips without paying a transaction tax. Come on. It’s time for the financial sector to grow up and pay its way like the rest of us.

Thank goodness a very taxing 2009 is just winding to a close this week. The financial crisis was caused by a high-rolling gambling addiction, and the globe’s citizens, with the help of their political leaders, went and did the rescue thing. Now it’s time to turn the tables.